Question

Somas dos termos da pg
Encontre o 8 termo da PG
(16,8,4,...)

Answer 1

Resposta:S8=510/16

Explicação passo a passo:

a1=16,q=a2/a1--->q=8/16:8/8--->q=1/2,n=8,S8=?

Sn=a1.[(q^n)-1]/q-1

S8=16.[(1/2^8)-1][1/2-1]

S8=16.[1/256-1]/[1/2-2/2]

S8=16.[1/256-256/256]/[-1/2]

S8=16.[-255/256]/[-1/2]

S8-4080/256/-1/2

S8=-8160/-256(-1)

S8=8160/256:16/16

S8=510/16